Barakat syndrome.

Barakat syndrome, also known as HDR syndrome, is a clinically heterogenous, autosomal dominant rare genetic disease, which frequency is unknown. It is primarily caused by deletion of chromosome 10p14 or mutation of GATA3 gene, located on chromosome 10. Although this syndrome is phenotypically defined by its triad of HDR: hypoparathyroidism (H), deafness (D), renal disease (R), the literature identifies cases with different components, consisting of HD, DR, HR (1). The syndrome was first described by Amin J. Barakat et al. in 1977 in siblings with hypocalcemia and proteinuria (2). So far, about 180 cases have been reported in the worldwide medical literature (3). In this report we present our own case report of patient with Barakat syndrome with hypoparathyrodism, unilateral deafness and renal impairment.

A Minimally Invasive, Fast Spinal Cord Lateral Hemisection Technique for Modeling Open Spinal Cord Injuries in Rats.

Open spinal cord injury techniques modeling laceration-like injuries are time-consuming and invasive because they involve laminectomy. This new technique eliminates laminectomy by removing two spinous processes and lifting, then tilting the caudal vertebral arch. The surgical area opens up without the need for laminectomy. Lateral hemisection is then performed with direct visible control under a microscope. The trauma is minimized, requiring only a small bone wound. This technique has several advantages: it is faster and, therefore, less of a burden for the animal, and the bone wound is smaller. Because the laminectomy is eliminated, there is less chance for unwanted injury to the spinal cord, and there are no bone splinters that can cause problems (bone splinters embedded in the spinal cord can cause swelling and secondary damage). The vertebral canal remains intact. The main limitation is that the hemisection can only be performed in the intervertebral spaces. The results show that this technique can be performed much faster than the traditional surgical approach, using laminectomy (11 min vs. 35 min). This technique can be useful for researchers working with animal models of open spinal cord injury as it is widely adaptable and does not require any additional specialized instrumentation.

SARS-CoV-2 RNA in the Cerebrospinal Fluid of a Patient with Long COVID.

Over 10% of COVID-19 convalescents report post-COVID-19 complications, namely, 'long COVID' or 'post-COVID syndrome,' including a number of neuro-psychiatric symptoms. The pathophysiology of COVID-19 in the central nervous system is poorly understood but may represent post-COVID injury, ongoing sterile maladaptive inflammation, or SARS-CoV-2 persistence. We describe a long COVID patient with SARS-CoV-2 RNA in the cerebrospinal fluid, which seems important, specifically due to recent reports of gray matter volume loss in COVID-19 patients. Further studies of SARS-CoV2 RNA, markers of inflammation, and neuronal damage in the CSF of patients with long COVID would be useful and should address whether the CNS can serve as a reservoir of SARS-CoV-2, clarify the pathway by which COVID-19 contributes to CNS dysfunction, and how best to therapeutically address it.

Effect of rat spinal cord injury (hemisection) on the ex vivo uptake and release of [3H]noradrenaline from a slice preparation.

We measured the ex vivo uptake and release of [3H]noradrenaline ([3H]NA) from perfused rat spinal cord slice preparations at 1, 3 and 14days after unilateral hemisection-induced spinal cord injury (SCI) compared with control slice preparations. After surgical hemisection under anaesthesia, the rats showed characteristic signs of hemiplegia, with no movement of the ipsilateral hindlimb. After 3days, the electron microscopy images showed overall degeneration of neuronal organelles and the myelin sheath, but the synapses seemed to be intact. In ex vivo experiments, the spinal cord injury did not influence uptake but increased [3H]NA release at rest and in response to axonal stimulation. The effect of a selective noradrenaline reuptake inhibitor, nisoxetine, was studied to identify the mechanisms underlying the increase in NA release. Nisoxetine potentiated stimulation-evoked [3H]NA release from the non-injured tissue, but it gradually lost its effectiveness after injury, depending on the time (1 and 3days) elapsed after hemisection, indicating that the noradrenaline transporter binding sites of the terminals become impaired after decentralisation.

[Chronic kidney diseases, metformin and lactic acidosis]. / Chronická oblicková choroba, metformín a laktátová acidóza.

Chronic kidney disease and diabetes mellitus represent a worldwide public health problem. The incidence of these diseases is gradually growing into epidemic proportions. In many cases they occur simultaneously, what leads to increased morbidity and mortality among the affected patients. The majority of the patients treated for diabetes mellitus are unaware of the presence of renal insufficiency. Vascular hypertrophy and diabetic kidney disease in patients with type 2 diabetes are the most common causes of kidney failure in countries with advanced healthcare systems. Metformin is a basic drug used for the treatment of type 2 diabetes mellitus. It is excreted in an unchanged form by the kidneys. When administered to patients with renal insufficiency, sepsis, dehydration or after the parenteral administration of iodinated contrast agents, metformin can cause lactic acidosis, which is also associated with an increased mortality rate.

Correlation between the increased release of catecholamines evoked by local anesthetics and their analgesic and adverse effects: Role of K(+) channel inhibition.

Because local anesthetics are known to inhibit both sodium and potassium channels, and anesthetic properties have been attributed to the former effect, we compared their effects with those of tetrodotoxin (TTX), a selective Na(+) channel inhibitor with anesthetic activity, and 4-aminopyridine (4-AP), a selective potassium channel blocker with convulsive activity, on transmitter release during rest and in response to field (axonal) stimulation using the microvolume perfusion method and isolated prefrontal cortex and spinal cord slice preparations loaded with the radioactive transmitters [(3)H]dopamine ([(3)H]DA) and [(3)H]noradrenaline ([(3)H]NA). It is also known that local anesthetics may exert analgesic effect and, rarely, some adverse effects on the central nervous system (CNS). Neurochemical evidence demonstrated that local anesthetics administered at concentrations ranging from 0.5 to 5mM, which might have been intentionally or accidentally achieved in clinical practice (e.g., during spinal and epidural anesthesia or peripheral nerve block), led to presynaptic failures during neurochemical transmission, including inhibited transmitter release associated with axonal firing and markedly enhanced extraneuronal concentrations of transmitters due to increased resting, [Ca(2+)]o-independent release. Tetrodotoxin, a toxin with selective Na(+) channel-blocking properties, inhibited the stimulation-evoked release but failed to affect the resting release. In contrast, the potassium channel inhibitor 4-AP enhanced both the resting- and action potential-evoked transmitter releases. It is concluded that effects of local anesthetics on resting catecholamine release in the spinal cord may contribute to their action during neuropathic pain relief and spinal analgesia as well as to their side effects in the CNS.